Crystal structure of (E)-2-[(2-bromopyridin-3-yl)methyl-idene]-6-meth-oxy-3,4-di-hydro-naphthalen-1(2H)-one and 3-[(E)-(6-meth-oxy-1-oxo-1,2,3,4-tetra-hydro-naphthalen-2-ylidene)meth-yl]pyridin-2(1H)-one

Crystal structure of (E)-7-methoxy-2-(4-methoxy-2-(trifluoromethyl)benzylidene)-3,4-dihydronaphthalen-1(2H)-one, C20H17F3O3

C20H17F3O3, monoclinic, P21/c (no. 14), a = 9.0684(4) Å, b = 13.1942(6) Å, c = 13.7883(7) Å, β = 96.250(5)°, V = 1639.97(13) Å3, Z = 4, R gt (F) = 0.0415, wR ref (F 2) = 0.1125, T = 100 K.

Crystal structure of (E)-7-methoxy-2-((5-methoxypyridin-3-yl)methylene)-3,4- dihydronaphthalen-1(2H)-one, C18H17NO3

C18H17NO3, triclinic, P 1 ‾ $P‾{1}$ (no. 2), a = 7.3950(5) Å, b = 8.6697(5) Å, c = 11.6813(9) Å, α = 85.457(6)°, β = 76.712(6)°, γ = 82.759(5)°, V = 722.07(9) Å3, Z = 2, R gt (F) = 0.0502, wR ref (F 2) = 0.1342, T = 99.9(3) K.

(E)-1-(Benzo[d][1,3]dioxol-5-yl)-3-([2,2'-bi-thio-phen]-5-yl)prop-2-en-1-one: crystal structure, UV-Vis analysis and theoretical studies of a new π-conjugated chalcone

In the title compound, C18H12O3S2, synthesized by the Claisen-Schmidt condensation method, the essentially planar chalcone unit adopts an s-cis configuration with respect to the carbonyl group within the ethyl-enic bridge. In the crystal, weak C-H⋯π inter-actions connect the mol-ecules into zigzag chains along the b-axis direction. The mol-ecular structure was optimized geometrically using Density Functional Theory (DFT) calculations at the B3LYP/6-311 G++(d,p) basis set level and compared with the experimental values. Mol-ecular orbital calculations providing electron-density plots of HOMO and LUMO mol-ecular orbitals and mol-ecular electrostatic potentials (MEP) were also computed both with the DFT/B3LYP/6-311 G++(d,p) basis set. The experimental energy gap is 3.18 eV, whereas the theoretical HOMO-LUMO energy gap value is 2.73 eV. Hirshfeld surface analysis was used to further investigate the weak inter-actions present.